Friday, August 10, 2007 - 10:30 AM

COS 159-8: The role of frugivorous birds and giant fruit bats as agents for reforestation in south India

Timothy T. Caughlin1, T. Ganesh2, and Margaret D. Lowman1. (1) New College of Florida, (2) Ashoka Trust for Research in Ecology and the Environment

Tropical forest restoration in open areas is often slowed by
limited seed rain and unfavorable conditions for tree seedling establishment.
Isolated remnant trees, a common feature of degraded anthropogenic landscapes,
may alleviate these problems. Remnant trees increase seedling recruitment in
part by attracting frugivorous animals, which amplify the quantity and
diversity of seed rain. We examined the sensitivity to human disturbance
of volant frugivore visitation to remnant trees in a
highly disturbed site of Tamil Nadu, India. Frugivorous
bird and Indian flying fox (Pteropusgiganteus) visitationto banyan trees (Ficusbenghalensis) was
recorded across a gradient of human impact, from urban areas to forest edge. Variables
quantifying disturbance, including building cover and the amount of vegetation
surrounding banyan trees, had relatively little effect on frugivore visitation.
For both groups of animal, the most important variable predicting visitation
was the size of the focal tree. In our study site, tree seedling abundance and
species richness is significantly higher under remnant trees compared to open
areas. These results demonstrate that animal seed dispersal, one of
the mechanisms leading to remnant tree function as recruitment foci, may
be resilient to disturbance. In some regions, incorporating
animal seed dispersal services into reforestation plans may increase the
efficiency of ecological restoration.